The invention relates to rolling machines or rolling mills in general, and more particularly to improvements in rolling machines with exchangeable rolling tools.
A rolling machine normally comprises a base which carries one or more frames for one or more pairs of complementary rotary rolling tools, e.g., tools in the form of parallel profiling rolls defining a nip for the passage of a strip of metallic or other material. If the machine comprises two or more pairs of rolling tools, such pairs are disposed one after the other in the direction of advancement of the workpiece so that the workpiece first passes through the nip of the rearmost pair of rolls and so on until it reaches and advances through the nip of the foremost rolls. It is further known to place a drive for the rolls next to the frame or next to the respective frames on the base of the rolling machine. The drive is provided with rotary clutch elements which engage and transmit torque to complementary clutch elements of the rolls, and the clutch elements of the drive normally receive torque by way of one or more universal joints, e.g., by way of cardan joints. Universal joints are desirable if the respective pair of rolls is to be replaced with a different pair of rolls so that it is necessary to change the level of clutch elements which form part of or are driven by the cardan joints. Rolling machines of the above outlined character are often used for the profiling of strips or webs which are made of metallic sheet material. An advantage of such machines is that the article which leaves the machine can exhibit a very complex profile as well as that the rolling operation is fast and can be carried out with a high degree of accuracy.
A drawback of heretofore known rolling machines of the above outlined character is that each change of setup takes up a relatively long interval of time. Even the replacement of a single pair of rolling tools is a time-consuming operation which entails a pronounced reduction of the output. Each change of setup necessitates disengagement of clutch elements on the cardan joints from the clutch elements of the rolling tools in the frame which must be replaced, the frame must be removed form the machine, a new frame must be inserted into the machine, and the clutch elements of rolling tools in the new frame must be attached to the corresponding clutch elements of the drive.
German Auslegeschrift No. 24 39 017 of Ruppel discloses a rolling machine with an arrangement which is to facilitate speedier replacement of pairs of rolling tools. More specifically, Ruppel proposes to accelerate the adjustment of rolling tools in a freshly inserted frame. The adjustment accelerating device includes a pair of yokes with legs which are pivotally secured to each other and the free ends of which can be coupled to one another by a link to thereby maintain the axes of tools in a freshly installed frame in optimum positions of exact registry with the axes of torque-transmitting clutch elements. Savings in time which are achieved with such yokes are negligible. Moreover, many operations must be carried out by hand and/or must be supervised by several attendants.
German Offenlegungsschrift No. 25 56 974 of Hof proposes to employ frames with pairs of coaxial turntables and with several rolling tools between each pair of coaxial turntables. The turntables of a selected pair are indexed when the operators desire to move a different rolling tool to the operative position. A drawback of the proposal of Hof is that the number of different pairs of rolling tools is limited to the number which can be accommodated between two coaxial turntables. Moreover, accurate positioning of turntables in selected positions presents many additional problems and the dimensions of rolling tools cannot be selected at will because the weight-carrying capacity of the turntables is limited. It has been found that such machines cannot turn out rolled material of high quality because the turntables are invariably mounted with a certain amount of play which compounds the tolerences attributable to the rolling tools.
Published Japanese patent application No. 59-218221 of Iwasaki and published German patent application No. 22 43 534 of Colbath disclose cold roll forming machines wherein the frame for the profiling rollers must be shifted axially of the rollers preparatory to being removed from the machine for replacement with a different frame. The removal further involves lifting subsequent to shifting in the axial direction of the rollers and away from the means for rotating the rollers. The introduction of a fresh frame is carried out by reversing the just described sequence of steps. Such mode of replacing frames for profiling rollers is not satisfactory because the machine occupies a substantial amount of space in the axial direction of the rollers.